This invention relates to shingles having multiple blend drops of granules and to methods and apparatus for depositing multiple blend drops onto a moving substrate.
A common method for the manufacture of asphalt shingles is the production of a continuous strip of asphalt shingle material followed by a shingle cutting operation which cuts the material into individual shingles. In the production of asphalt strip material, a substrate such as an organic felt or a glass fiber mat is passed through a coater containing liquid asphalt to form a tacky asphalt coated strip. Subsequently, the hot asphalt strip is passed beneath one or more granule applicators which apply the protective surface granules to portions of the asphalt strip material. Typically, the granules are dispensed from a hopper at a rate which can be controlled by making adjustments to the flow of granules discharged from the hopper. In the manufacture of colored shingles, two types of granules are employed. Headlap granules are granules of relatively low cost for portions of the shingle which are to be covered up when the shingles are installed on a roof. Colored granules or prime granules are of relatively higher cost and are applied to the portion of the shingle which will be exposed on the roof.
Not all of the granules applied to the hot, tacky, asphalt coated strip adhere to the strip, and, typically, the strip material is turned around a slate drum to invert the strip and cause the non-adhered granules to drop off. These non-adhered granules, which are known as backfall granules, are usually recovered by collecting them in a backfall hopper. The backfall granules are eventually recycled and discharged onto the sheet.
To provide a color pattern of pleasing appearance the colored shingles are provided in different shades or color variations of the predominant color, usually in the form of a predominant background color and a series of granule deposits of different colors or different shades from the background color. These highlighted series of deposits, referred to as blend drops, are typically made by discharging granules from a series of blend drop granule dispensers that are positioned upstream from the background granule dispenser.
It would be advantageous if there could be developed a shingle, and a method and apparatus for making such a shingle, where the deposits of blend drop granules could be used to provide an even more aesthetically pleasing appearance when the shingle is applied with similar shingles on a roof.
The above objects as well as other objects not specifically enumerated are achieved by a method of making shingles, where the method includes providing a moving asphalt coated sheet having at least an overlay lane and an underlay lane. Blend drops of at least two color blends are discharged onto each lane, wherein at least one of the blend drops discharged onto the overlay lane has a different color blend from the color blends of all the blend drops discharged onto the underlay lane. Background granules are then discharged onto the asphalt coated sheet to form a granule coated sheet, and the excess granules are removed from the granule coated sheet.
According to this invention there is also provided a method of making shingles, where the method includes providing a moving asphalt coated sheet having an overlay lane, a middle lane and an underlay lane. Blend drops of at least two color blends are discharged onto each lane, wherein each lane has a combination of color blends for the blend drops different from the combination of color blends for the blend drops of the other two lanes. Background granules are discharged onto the asphalt coated sheet to form a granule coated sheet, and excess granules are removed from the granule coated sheet. The granule coated sheet is divided into continuous overlay, middle and underlay strips, and the continuous overlay, middle and underlay strips are laminated together to form trilaminate shingles.
According to this invention there is also provided a plurality of laminated shingles, each shingle comprising an overlay sheet and an underlay sheet. The overlay sheets have a prime area that is substantially covered with granules, including one or more blend drops from a first group of blend drops of at least two color blends. The underlay sheets are substantially covered with granules, including one or more blend drops from a second group of blend drops of at least two color blends. At least one of the color blends of a blend drop of the first group of blend drops is a different color from the color blends of all of the blend drops of the second group.
According to this invention there is also provided a plurality of trilaminated shingles, each shingle comprising an overlay sheet, a middle sheet and an underlay sheet. The overlay sheets have a prime area that is substantially covered with granules, including one or more blend drops from a first group of blend drops of at least two color blends. The underlay sheets are substantially covered with granules, including one or more blend drops from a second group of blend drops of at least two color blends. The middle sheets are substantially covered with granules, including one or more blend drops from a third group of blend drops of at least two color blends. The collection of the color blends for the blend drops of each of the first, second and third groups of blend drops is different from the collection of color blends for the blend drops of the other groups of blend drops.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings.